1. Field of the Invention
The invention concerns, generally speaking, memory cards having at least one active electronic component housed in a cavity of said card and, more particularly, a support for a component of this type.
2. Description of the Prior Art
Identification cards are used in many fields, especially in the field of bank cards or credit cards. However, for a long time, apart from an identification number and the bearer's number, these cards have had only a magnetic recording enabling identification by magnetic reading. For many years now, these cards have been used for other functions than for identifying the bearer and, especially, for prepayment and protection against fraudulent activities. To this end, the card has an active electronic component which may consist of an electronic memory which may or may not be associated with a microprocessor, thus enabling its use notably for banking type applications.
Credit cards made with this technology, which have an electronic component, are manufactured in various ways. According to a first method, a cavity is made in the thickness of the card to accommodate the electronic component. According to another method, known as "co-lamination", thin layers of plastic material, such as polyepoxy, polyethylene, polyvinyl chloride etc. are laminated around the component. During the implementation of these methods, various other operations are further performed to electrically connect the terminals of the electronic component with metallizations placed on the surface of the card.
One of the methods used to install the electronic component in the cavity made in the card and to place metallizations on the card, as well as to make the connections between the terminals of the card and the metallizations consists, as shown in FIG. 1, in the use of a non-conductive film 1, made of polyepoxy for example. This film has, on one side, the electronic component in the form of a chip 2 and, on the other side, metallized surfaces such as those marked 3, 4 and 5, separated from one another by spaces 6 and 7 without metallization. These metallized surfaces 3, 4 and 5 communicate with the other side of the film 1 by means of holes 8, 9 and 10 through which the ends of the conducting wires 11, 12 and 13 are connected with the corresponding metallized surfaces by any known means such as a conductive bonder. The other end of each conducting wire is connected to an output terminal 14, 15 or 16 of the chip 2.
These operations are then followed by the coating of the chip 2 with resin and curing of the resin, by heat, to encapsulate the chip. The chip can then be installed in the cavity of the card and the metallizations can be placed at the edge of the cavity by simply fitting in the chip and bonding the support film 1 to the card after it has been cut out to the requisite dimensions.
A method of this type results in a structure in which the chip 2 is bonded to the frame 1, to which adheres a layer of metallic zones. The set formed by the film and the metallic layer is relatively flexible. It is more flexible than the card made of polyepoxy, while the chip, the base of which is a silicon base or substrate which is several hundreds of microns thick (for example, 280 microns thick) is rigid, hard and brittle. This results in strains, particularly when the identification or identity card is handled without precautions. These strains cause breaks in the silicon substrate and, hence, the destruction of the chip.
One solution to this problem consists in increasing the thickness of the silicon substrate, but this approach is limited by the depth of the card. Moreover, a greater thickness naturally increases the overall mechanical strength of the chip, but the chip remains fragile with respect to shocks.
The object of the present invention, therefore, is to make an electronic component support the overcomes the above-mentioned drawbacks, without any increase in the thickness of the final component, and which protects the electronic component from mechanical damage which may be caused, in particular, by violent handling of the card in which the component is housed.